Year % change from 1990 1991 0.756252062382656 1992 1.4905955349753 1993 1.99016547747202 1994 2.75642516728967 1995 3.45885242265727 1996 3.86537847765054 1997 4.30571408478893 1998 5.02653373652351 1999 5.91991734240691 2000 7.05591829448391 2001 7.898452333941 2002 8.76857496794854 2003 9.58784803552977 2004 10.5694069534077 2005 11.3570342801811 2006 12.3396751037277 2007 13.3547730973336 2008 14.4042215959191 2009 14.8039857404833 2010 15.9237581075306 2011 17.0829956886059 2012 18.2422332696812